The electron density measurement system which utilizes the change of resonance frequency of the open die resonator which stores the plasma and the plasma

摘要

(57) Abstract Topic SolutionsTo measure plasma electron density (for example range of 1010 or 1012 cm ^-3), in the system in order to control the plasma generator, as for measurement of plasma electron density, it is used as portion of closed-loop control in plasma assist processing like accumulating or etching. Plasma measuring method and the system generate control voltage. This voltage controls the plasma generator. Program possible frequency source excites the plural resonance modes of the open type resonator which is located inside the plasma processor continually. As for resonance frequency of resonance mode, it responds to the plasma electron density inside the space between the reflectors of the open type resonator. The device decides the increase of resonance frequency of the resonance mode which is selected optionally with the introduction of the plasma, in the open type resonator automatically, this compares with the frequency which is decided and the data which is input beforehand.